Abstract
Abstract: :
Purpose: TIP120A is a transcription factor in eukaryotic cells. It is thought to coordinate gene expression during cell growth and/or differentiation. In the visual system, TIP120A has not been studied and its function is not known. This study evaluates that TIP120A in the retina, RPE and RPE/choroid and follows changes in the expression after retinoic acid treatment. Methods: Eyes (adult BALB/c and C57BL/6J mice and adult Sprague-Dawley rats) were fixed in 4% paraformaldehyde and prepared for immunohistochemical analysis. Rat RPE-J cells were incubated for 8 days with/without retinoic acid. Total RNA was isolated and TIP120A mRNA changes were studied by RT-PCR. TIP120A polyclonal antibody was prepared in rabbit. Western blot analysis of the RPE-J cells with/without retinoic acid was performed. Results: TIP120A is strongly immunoreactive in RPE cells. RPE cell nuclei are intensively stained. RT-PCR and Western blot analysis indicated that TIP120A is expressed in RPE-J cells. Furthermore, TIP120A increased following retinoic acid treatment in both mRNA and protein. Immunoprecipitation showed that TIP120A forms a physical complex with TATA-binding protein in RPE-J cells. Conclusion: TIP120A is expressed in RPE cells. Endogenous TIP120A and TATA-binding protein interact in RPE J-cells. The present data suggest that TIP120A may play a regulatory role in RPE cells, possibly through interacting with TATA-binding protein. The prominent TIP120A in the RPE and the interaction with TATA-binding protein suggest that additional studies are needed to clarify the role and function of this regulatory molecule in retinal tissues.
Keywords: 567 retinal pigment epithelium • 605 transcription factors